This invention relates to automatic analysis apparatus in general and more particularly to an improved sponge irrigation system for use in such analysis apparatus.
In a copending application of John G. Atwood et al, Ser. No. 594,951 filed July 10, 1975 as a continuation of now abandoned application Ser. No. 499,602, filed Aug. 22, 1974 and assigned to the same assignee as the present invention, a completely automatic kinetic analysis apparatus is disclosed. In that apparatus sponge wipers are employed to wipe off the tips of pipettes, probes, etc., to control the size of the drop on the tip thereof and to reduce sample carry over. For such a spong wiping system to be effective the sponges must be irrigated so that contamination is removed and a fresh supply of irrigating liquid provided to each sponge. In the prior art such has been accomplished in similar devices by periodically removing and washing the sponge. Clearly in a completely automated apparatus which is designed for unattended use over extensive periods of time such a solution is unacceptable.
In view of this the need arises to irrigate the sponges continually supplying fresh irrigation liquid thereto and removing contaminated liquid. On the surface this might suggest simply supplying each of the sponges with a liquid supply and drawing liquid away therefrom with common means. Such is not effective because of different physical locations of the sponges at different distances from a source and unequal irrigation occurs with only the sponge nearest the source being properly irrigated. Of course another solution would be to separately irrigate each sponge. However, such becomes unduly expensive.
Thus, the need for a simple and effective device which can equally irrigate a plurality of sponges becomes evident.